What is the drip factor for IV (intravenous) therapy when mixing vitamin C (ascorbic acid) 1000mg in a 100ml Normal Saline (NS) bag?

Drip Factor for IV Vitamin C Administration

The drip factor (drops per milliliter) depends entirely on your IV administration set, not the medication itself—standard macrodrip sets deliver 10,15, or 20 drops/mL, while microdrip sets deliver 60 drops/mL.

Understanding Drip Factors

The drip factor is a property of the IV tubing, not the solution being infused:

• Macrodrip sets: Typically deliver 10,15, or 20 drops/mL depending on manufacturer
• Microdrip sets: Deliver 60 drops/mL (also called pediatric sets)

To calculate your drip rate: Check the packaging of your specific IV administration set for the drip factor, then use the formula: (Total volume in mL × Drip factor) ÷ Time in minutes = Drops per minute

Vitamin C IV Administration Considerations

Preparation and Compatibility

• Vitamin C (ascorbic acid) is highly susceptible to oxidation and requires specific handling precautions 1
• The solution can be mixed in normal saline as you've described 2
• Light protection is strongly recommended for both the bag and administration set, as vitamin C undergoes significant photo-degradation that can have clinical impact 1
• Use multi-layer bags impermeable to oxygen when possible to minimize oxidation 1

Infusion Rate Guidance

For a 100 mL bag containing 1000 mg vitamin C:

• Typical infusion time: 30-60 minutes for this volume and dose
• If using a standard macrodrip set (20 drops/mL) infused over 30 minutes: (100 mL × 20 drops/mL) ÷ 30 min = 67 drops/minute
• If using a microdrip set (60 drops/mL) infused over 30 minutes: (100 mL × 60 drops/mL) ÷ 30 min = 200 drops/minute

Important Safety Considerations

Monitor for specific complications associated with IV vitamin C:

• Hypernatremia: Particularly relevant when using normal saline as your diluent 3
• Glucometer interference: High-dose vitamin C can cause falsely elevated glucose readings on some glucometers 3
• Oxalate nephropathy: Rare but reported with high doses; ensure adequate hydration 3
• Hemolysis in G6PD deficiency: Screen patients before administration 3

Dosing Context

• Your 1000 mg dose is considered moderate; doses up to 3 g/day orally or 2-3 g/day IV are used to restore normal plasma concentrations in deficiency states 1
• IV administration bypasses tight oral absorption control and produces significantly higher plasma concentrations than oral dosing 4, 5
• Doses above 1000 mg daily may increase oxalate and urate excretion 6

Practical Administration Steps

1. Verify your IV set's drip factor from the package labeling
2. Protect the solution from light using an opaque cover or light-protective administration set 1
3. Calculate drops/minute using the formula above based on your desired infusion time
4. Monitor the patient during infusion for any adverse reactions
5. Ensure adequate urine output to facilitate renal excretion 7